RU2640711C2 - Method of obtaining protection elements and hologram - Google Patents

Abstract

FIELD: physics.SUBSTANCE: method of forming a surface microstructure, especially on a substrate, comprises the steps of: A) applying a curable composition to, at least, a portion of the substrate, wherein the said curable composition comprises: a1) at least, one ethylenically unsaturated resin, a monomer, or a mixture thereof; a2) at least, one photoinitiator and a3) a metallic pigment, which is in the form of plated shaped transition metal particles having a largest edge length dimension of 5 to 1000 nm, preferably from 7 to 600 nm and in particular from 10 to 500 nm, and a thickness of 1 nm to 100 nm, preferably from 2 to 40 nm, and in particular from 3 to 30 nm; wherein the weight ratio of the metallic pigment to the binder is from 5: 1 to 1: 1000; B) contacting, at least, a portion of the curable composition with the surface microstructure, especially forming an optically variable image agent; C) curing the composition by using, at least, one UV lamp.EFFECT: present invention makes it possible to print microstructures on a substrate, providing relief and metallizing the surface relief in a single technological step using a conventional printing system.18 cl, 1 dwg

Description

The present invention relates to a method for forming a microstructure of a surface topography, especially an optically variable image (optically variable device) on a substrate, in particular on a transparent or translucent substrate, and a means obtained using the method. An additional objective of the invention is to use to prevent falsification or reproduction of a security and a method of forming a coating exhibiting a color change depending on the angle.

Earlier, many attempts were made to improve the manufacture of protective elements for the formation of optically variable images (optically variable devices, OPU) on the substrate.

WO2005051675 is directed to a method for forming a holographic diffraction grating on a substrate, comprising the steps of: a) applying a curable compound to at least a portion of the substrate; b) contacting at least a portion of the curable compound with a diffraction grating means; c) curing the curable compound; and d) depositing metallic ink on at least a portion of the cured compound.

WO 2011/064162 discloses the use of coating compositions containing shaped transition metal particles, especially silver, and a binder, wherein the ratio of pigment to binder is preferably such that the resulting coating exhibits a color change depending on the angle to obtain security elements and holograms. In the case of using the coating compositions according to the invention in the coating of a hologram, the obtained means show a color change depending on the angle (trigger effect), different colors in reflection and transmission. The production method includes two stages. First, usually a transparent binder is applied, on which the OPA image is printed in relief, and then cured. In the second stage, the coating is applied to an OPD image containing particles with nanosizes of a specific geometry.

It has now been found that the process can be greatly simplified without sacrificing optical properties, such as high contrast, strong dependence of the viewing angle and high productivity, through the use of a one-step process, which means only one stage of the relief and one stage of curing. The coating is a UV curable composition that further comprises specifically formed metal particles. The term coating is used in this context as a synonym for ink or varnish.

In one embodiment, a particular feature of the process is that the curing step is carried out through the back side of the substrate, which therefore must be transparent or translucent. This is an advantage, since a traditional rotary metal printing press with corresponding embossed devices attached to the surface can be used for embossing.

Alternatives for curing from the front are so-called transparent gaskets, which have several drawbacks. Quartz is not strong enough and leads to a slow process. In addition, transparent pads (tapes or sleeves) can only be used several times due to aging under UV radiation (polymer pads) and printing on the recorder is very difficult.

There is a need for effective systems and methods for printing microstructures (surface topography structures) on a substrate, in particular a transparent or translucent substrate, which fully incorporates surface topography technologies into widespread printing products, such as classified documents, flexible and rigid packaging, labels and printing forms .

The present invention makes it possible to print microstructures on a substrate, in particular on a transparent or translucent substrate, imparting relief and metallizing the surface relief at one technological stage using a traditional printing system such as flexography, rotogravure, offset printing, silk screen printing, digital printing and inkjet printing.

One aspect of the invention is a method of forming a microstructure of a relief surface, especially an optically variable image (optically variable device, OPD) on a substrate, comprising the steps of:

A) applying a curable composition to at least a portion of a substrate in which the curable composition comprises

a1) at least one ethylenically unsaturated resin, monomer or mixture thereof;

A2) at least one photoinitiator; and

A3) a metal pigment which is in the form of molded plates of transition metal particles having the largest edge lengths from 5 nm to 1000 nm, preferably from 7 nm to 600 nm, and in particular from 10 nm to 500 nm, and a thickness from 1 nm to 100 nm, preferably from 2 to 40 nm, and in particular from 3 to 30 nm;

B) contacting at least part of the curable composition with the microstructure of the surface topography, especially forming an optically variable image means;

C) curing the composition by using at least one UV lamp.

In a particular embodiment of the invention, there is provided a method of forming a microstructure of a surface topography, especially an optically variable image (optically variable device, OPD) on a transparent or translucent substrate, comprising the steps of:

A) applying a curable composition to at least a portion of the front side of the substrate, where the curable composition contains

a1) at least one ethylenically unsaturated resin, monomer or mixture thereof;

A2) at least one photoinitiator; and

A3) a metal pigment which is in the form of molded plates of transition metal particles having the largest edge lengths from 5 nm to 1000 nm, preferably from 7 nm to 600 nm, and in particular from 10 nm to 500 nm, and a thickness from 1 nm to 100 nm, preferably from 2 to 40 nm, and in particular from 3 to 30 nm;

B) contacting at least part of the curable composition with the microstructure of the surface topography, especially forming an optically variable image;

C) curing the composition by using at least one UV lamp, which is located on the back side of a transparent or translucent substrate.

Basically, the invention is carried out in apparatus for forming a microstructure of a surface topography on a substrate, which is coated with a curable composition (varnish) at least on a portion of the front side comprising a printing press and forming a microstructure of the surface topography, wherein the microstructure forming agent contains

a) forming a microstructure of the surface topography, especially a gasket that puts the microstructure in a curable composition, and

b) a lamp having a radiation peak (s) in the UV-A range and preferably close to the VIS (optical) range for curing the curable composition when the coated substrate is pressed relative to the spacer.

In a preferred embodiment, the (printing) apparatus comprises

a) a mechanism for feeding the substrate through the apparatus,

b) a coating section containing a source of liquid curable UV composition and means for applying a liquid composition from the source to the surface of the substrate,

c) a relief embossing / curing section for pressing the microstructure (surface relief) into the surface of the deposited composition on the substrate, and means for curing the resin having the microstructure (surface relief) pressed into it so that the microstructures are stored in the cured resin, where the apparatus is located so so that the composition is applied to the upper surface of the substrate, so that the means for pressing the microstructure (surface topography) is a nickel plate mounted in an opaque cylin dr or a metal cylinder having a microstructure (surface topography) and two pressure rollers that are in contact with the back surface of the substrate and which have an axis of rotation that is along the same axis as the axis of rotation of the cylinder, and the means for curing the resin is a UV source radiation located on the back surface of the substrate.

In one embodiment, the apparatus may be a stand-alone or stand-alone device, or in an alternative preferred embodiment, the apparatus may be a continuous or integrated system with other additional conventional printing, laminating, cutting, slitting, and other conversion substations as part of an integrated manufacturing process. In one embodiment, the apparatus and processes can be designed and applied to provide partial holographic printing of a grid-based substrate. This can be achieved by partially printing radiation-curable varnish, such as, for example, graphic elements on a mesh-based substrate, and duplicating the surface microstructure of the surface only in areas where the radiation curable varnish is printed.

In a further embodiment, the apparatus may further comprise an additional curing element to the UV with or without a heating element, or only an IR heating element or combined UV / IR, which can be particularly recommended for supporting and accelerating the curing of varnish systems. This additional curing element can be used when the coated substrate emerging from the printing / curing element, although successfully printed, is not fully cured. An additional curing element ensures that the coating is fully cured.

According to the present invention, curing is preferably carried out through the substrate, and not through the gasket (UV radiation source located inside the opening of the hollow quartz cylinder, etc.).

The surface-forming microstructure of the surface relief is preferably a gasket selected from the group consisting of a nickel sleeve, a nickel plate, a metal drum etched or formed by a laser, or other materials mounted on an opaque cylinder or a metal cylinder containing an image on the surface of the OPA. The means forming the microstructure of the surface topography may comprise means for cooling.

The preliminary UV curing element can be positioned after the UV varnished element and before the embossing / curing element. The pre-curing element irradiates a radiation curable composition coated on a mesh substrate so that it is at least partially cured before it enters the embossing / curing unit.

Surface relief microstructures, such as holograms, can be quickly and accurately duplicated on a substrate by applying the method of the present invention and the apparatus described above. FIG. 1 shows a schematic representation of a suitable configuration as described above.

Preferably, the lamp used to cure the composition is a gallium or iron alloyed medium pressure mercury lamp.

Basically, the photoinitiator is selected from benzophenone, compounds such as alpha-hydroxyketones, compounds such as alpha-alkoxyketones, compounds such as alpha-aminoketones, compounds of oxides of mono- and bisacylphosphines, compounds of phenylglyoxylates, compounds of oxime esters and compounds of onium salts (compounds of sulfonium salts and salt compounds iodonium) and mixtures thereof.

For example, a photoinitiator is selected from compounds of mono- and bisacylphosphine oxides, compounds such as alpha-aminoketones, oxime ester compounds, and mixtures thereof.

In a preferred embodiment, the photoinitiator is selected from mono- and bisacylphosphine compounds and mixtures thereof.

Alternatively, the curable composition comprises a mixture of a mono- or bisacylphosphine oxide compound with a benzophenone compound, an alpha hydroxyketone compound, alpha alkoxy ketone compound or alpha aminoketone compound.

Currently, the most preferred photoinitiators are compounds of mono- and bisacylphosphine oxides. Compounds of mono- and bisacylphosphine oxides can be used separately. Alternatively, a mixture of the mono- and bisacylphosphine oxide compound can be used, or the mono- and bisacylphosphine oxide compounds can be used in admixture with other photoinitiators, such as, for example, benzophenone, alpha-aminoketone, alpha-hydroxyketone, ketal compounds, phenyl glyoxylate compounds, oxime ester compounds or onium salt compounds, especially benzophenone compound, alpha-hydroxyketone, alpha-alkoxyketone or alpha-aminoketone compound, especially benzophenone compound, compound alpha hydroxyketone or alpha alkoxyketone. The alpha-aminoketone compound can be used alone or in mixtures with other photoinitiators if yellowing is not a problem.

Examples of photoinitiators are known to the skilled person and, for example, are published by Kurt Dietliker in "A compilation of photoinitiators commercially available for UV today", Sita Technology Textbook, Edinburgh, London, 2002.

Examples of suitable acylphosphine oxide compounds have the formula XII

в которой

wherein

R ₅₀ represents unsubstituted cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl; or is cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl substituted with one or more halogen, C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ alkoxy, C ₁ -C ₁₂ alkylthio or NR ₅₃ R ₅₄ ;

or R ₅₀ is unsubstituted C ₁ -C ₂₀ alkyl or is C ₁ -C ₂₀ alkyl which is substituted with one or more halogen, C ₁ -C ₁₂ alkoxy, C ₁ -C ₁₂ alkylthio, NR ₅₃ R ₅₄ or - (CO) -O-C ₁ -C ₂₄ alkyl;

R ₅₁ represents unsubstituted cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl; or is cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl substituted with one or more halogen, C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ alkoxy, C ₁ -C ₁₂ alkylthio or NR ₅₃ R ₅₄ ; or R ₅₁ represents - (CO) R ′ ₅₂ ; or R ₅₁ is C ₁ -C ₁₂ alkyl which is unsubstituted or substituted by one or more halogen, C ₁ -C ₁₂ alkoxy, C ₁ -C ₁₂ alkylthio or NR ₅₃ R ₅₄ ;

R ₅₂ and R ′ ₅₂ independently of one another are unsubstituted cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl, or are cyclohexyl, cyclopentyl, phenyl, naphthyl or biphenylyl substituted with one or more halogen, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy; or R ₅₂ represents a heterocyclic ring with 5 or 6 members containing an S atom or an N atom;

R ₅₃ and R ₅₄ independently of one another are hydrogen, unsubstituted C ₁ -C ₁₂ alkyl or C ₁ -C ₁₂ alkyl substituted with one or more OH or SH, where the alkyl chain is optionally broken with one to four oxygen atoms, or R ₅₃ and R ₅₄ independently of one another is C ₂ -C ₁₂ alkenyl, cyclopentyl, cyclohexyl, benzyl or phenyl;

Specific examples are bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure ^® 819); oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine (Darocur ^® TPO); ethyl (2,4,6 trimethylbenzoylphenyl) phosphinic acid ester; (2,4,6-trimethylbenzoyl) -2,4-dipentoxyphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.

Of further interest are mixtures of compounds of formula XII with compounds of formula XI, as well as mixtures of various compounds of formula XII.

Examples are mixtures of bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide with 1-hydroxy-cyclohexyl-phenylketone, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide and 2-hydroxy-2-methyl -1-phenyl-propan-1-one, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide with ethyl (2,4,6 trimethylbenzoylphenyl) phosphinic acid ester, etc ..

Examples of suitable benzophenone compounds are compounds of formula X:

в которой

wherein

R ₆₅ , R ₆₆ and R ₆₇ independently of one another are hydrogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ haloalkyl, C ₁ -C ₄ alkoxy, Cl or N (C ₁ -C ₄ alkyl) ₂ ;

или

R ₆₈ represents hydrogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ haloalkyl, phenyl, H (C ₁ -C ₄ alkyl) ₂ , COOCH ₃ ,

or

Q is the residue of a polyhydroxy compound containing from 2 to 6 hydroxyl groups;

x is a number greater than 1, but not greater than the number of available hydroxyl groups in Q;

A represents - [O (CH ₂ ) _b CO] _y - or - [O (CH ₂ ) _b CO] _(y-1) - [O (CHR ₇₁ CHR ₇₀ ) a] _y -;

R ₆₉ represents hydrogen, methyl or ethyl; and if N is greater than 1,

R ₆₉ radicals may be the same or different from each other;

a is a number from 1 to 2;

b is a number from 4 to 5;

y is a number from 1 to 10;

n is; and

m is an integer of 2-10.

Specific examples are Darocur ^® BP (= benzophenone), Esacure TZT ^® , available from Lamberti, (a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone), 4-phenyl benzophenone, 4-methoxybenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-dimethylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4- (4-methylthiophenyl) benzophenone, 3 , 3'-dimethyl-4-methoxybenzophenone, methyl 2-benzoylbenzoate, 4- (2-hydroxyethylthio) benzophenone, 4- (4-tolylthio) benzophenone, 4-benzoyl-N, N, N-trimethylbenzenemethanamine chloride, chloro monohydrate yes 2-hydroxy-3- (4-benzoylphenoxy) -N, N, N-trimethyl-1-propanamino, 4- (13-acryloyl-1,4,7,10,13-pentaoxatridecyl) benzophenone, 4-benzoyl chloride -N, N-dimethyl-N- [2- (1-oxo-2-propenyl) oxy] ethylbenzenemethanamine; [4- (2-hydroxy-ethylsulfanyl) phenyl] - (4-isopropylphenyl) methanone; biphenyl- [4- (2-hydroxy-ethylsulfanyl) phenyl] methanone; biphenyl-4-yl-phenyl-methanone; biphenyl-4-yl-p-tolyl-methanone; biphenyl-4-yl-m-tolyl-methanone; [4- (2-hydroxy-ethylsulfanyl) phenyl] p-tolyl methanone; [4- (2-hydroxy-ethylsulfanyl) phenyl] - (4-isopropyl-phenyl) methanone; [4- (2-hydroxy-ethylsulfanyl) phenyl] - (4-methoxy-phenyl) methanone; 1- (4-benzoyl-phenoxy) -propan-2-one; [4- (2-hydroxy-ethylsulfanyl) phenyl] - (4-phenoxy-phenyl) methanone; 3- (4-benzoyl-phenyl) -2-dimethylamino-2-methyl-1-phenyl-propan-1-one; (4-chloro-phenyl) - (4-octylsulfanyl-phenyl) methanone; (4-chloro-phenyl) - (4-dodecylsulfanyl-phenyl) methanone; (4-bromo-phenyl) - (4-octylsulfanyl-phenyl) methanone; (4-dodecylsulfanyl-phenyl) - (4-methoxy-phenyl) methanone; (4-benzoyl-phenoxy) -acetic acid methyl ester; biphenyl- [4- (2-hydroxy-ethylsulfanyl) phenyl] methanone; 1- [4- (4-benzoilfenilsulfanil) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one (Esacure ^® 1001 available from Lamberti).

Examples of suitable alpha-hydroxyketone, alpha-alkoxyketone or alpha-aminoketone compounds are compounds of formula (XI)

в которой

wherein

R ₂₉ represents hydrogen or C ₁ -C ₁₈ alkoxy;

R ₃₀ represents hydrogen, C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ hydroxyalkyl, C ₁ -C ₁₈ alkoxy, OCH ₂ CH ₂ -OR ₃₄ , morpholino, S-C ₁ -C ₁₈ alkyl, the group —CH = CH ₂ , -

d, e and f are 1-3; s is 2-10;

G ₁ and G ₂ independently from each other are end groups of the polymer structure, preferably hydrogen or methyl;

или

;R ₃₄ represents hydrogen,

or

;

R ₃₁ represents hydroxy, C ₁ -C ₁₆ alkoxy, morpholino, dimethylamino or —O (CH ₂ CH ₂ O) _g —C ₁ -C ₁₆ alkyl;

g is 1-20;

R ₃₂ and R ₃₃ independently of one another are hydrogen, C ₁ -C ₆ alkyl, C ₁ -C ₁₆ alkoxy or —O (CH ₂ CH ₂ O) _g —C ₁ -C ₁₆ alkyl; or are unsubstituted phenyl or benzyl; or phenyl or benzyl substituted with C ₁ -C ₁₂ alkyl; or R ₃₂ and R ₃₃ together with the carbon atom to which they are attached form a cyclohexyl ring;

R ₃₅ represents hydrogen, OR ₃₆ or NR ₃₇ R ₃₈ ;

R ₃₆ represents hydrogen, C ₁ -C ₁₂ alkyl, which is optionally terminated by one or more non-consecutive O atoms and which is not terminated or terminated by C ₁ -C ₁₂ alkyl, optionally substituted with one or more OH,

;or R ₃₆ represents

;

R ₃₇ and R ₃₈ independently from each other represent hydrogen or C ₁ -C ₁₂ alkyl, which is unsubstituted or substituted by one or more OH;

;R ₃₉ is C ₁ -C ₁₂ alkylene, which optionally terminates with one or more non-sequential O, - (CO) -NH-C ₁ -C ₁₂ alkylene-NH- (CO) - or

;

with the proviso that R ₃₁ , R ₃₂ and R _{33 are} not all together C ₁ -C ₁₆ alkoxy or —O (CH ₂ CH ₂ O) _g —C ₁ -C ₁₆ alkyl.

Specific examples include 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure ^® 184) or Irgacur ^® 500 (mixture of Irgacure ^® 184 with benzophenone), 2-methyl-1 [4- (methylthio) phenyl] -2-morfolinopropan-1- he (Irgacure ^® 907), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (Irgacure ^® 369), 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (Irgacure ^® 379), (3,4-dimethoxy-benzoyl) -1-benzyl-1-dimethylaminopropane, 1- [4- (2-hydroxyethoxy ) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (Irgacure ^® 2959), 2,2-dimethoxy-1,2-diphenylethan-1-one (Irgacure ^® 651), 2-hydroxy -2-methyl-1-phenyl-propan-1-one (Darocur ^® 1173) 2-hydroxy-1- {4- [4- (2-hydroxy -2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one (Irgacure ^® 127), 2-gadroksi-1- {4- [4- (2-hydroxy-2-methyl- propionyl) phenoxy] phenyl} -2-methyl-propan-1-one, Esacure KIP provided by Lamberti, 2-hydroxy-1- {1- [4- (2-hydroxy-2-methyl-propionyl) phenyl ] -1,3,3-trimethyl-indan-5-yl} -2-methyl-propan-1-one.

Irgacure ^® and Darocur ^® are available from BASF SE.

Examples of suitable phenylglyoxylate compounds are compounds of formula XIII

в которой

wherein

R ₆₀ represents hydrogen, C ₁ -C ₁₂ alkyl or

R ₅₅ , R ₅₆ , R ₅₇ , R ₅₈ and R ₅₉ independently of one another are hydrogen, unsubstituted C ₁ -C ₁₂ alkyl or C ₁ -C ₁₂ alkyl substituted with one or more OH, C ₁ -C ₄ alkoxy, phenyl, naphthyl, halogen or CN; where the alkyl chain is optionally broken by one or more oxygen atoms; or R ₅₅ , R ₅₆ , R ₅₇ , R ₅₈ and R ₅₉ independently of one another are C ₁ -C ₄ alkoxy, C ₁ -C ₄ alkito, or NR ₅₂ R ₅₃ ;

R ₅₂ and R ₅₃ independently of one another are hydrogen, unsubstituted C ₁ -C ₁₂ alkyl or C ₁ -C ₁₂ alkyl substituted with one or more OH or SH, where the alkyl chain optionally breaks from one to four oxygen atoms; or R ₅₂ and R ₅₃ independently of one another are C ₂ -C ₁₂ alkenyl, cyclopentyl, cyclohexyl, benzyl or phenyl; and

Y ₁ represents C ₁ -C ₁₂ alkylene, which is optionally terminated by one or more oxygen atoms.

Specific examples of compounds of formula XIII are complicated 2- [2- (2-oxo-2-phenyl-acetoxy) -ethoxy] -ethyl ester oksofeniluksusnoy acid (Irgacure ^® 754), methyl α-oksobenzolatsetat.

Examples of suitable oxime ester compounds are compounds of formula XIV

в которой R72

in which R72

z is 0 or 1;

R ₇₀ represents hydrogen, C ₃ -C ₈ cycloalkyl; C ₁ -C ₁₂ alkyl which is unsubstituted or substituted by one or more halogen, phenyl or CN; or R ₇₀ is C ₂ -C ₅ alkenyl; phenyl which is unsubstituted or substituted by one or more C ₁ -C ₆ alkyl, halogen, CN, OR ₇₃ , SR ₇₄ or NR ₇₅ R ₇₆ ; or R ₇₀ is C ₁ -C ₈ alkoxy, benzyloxy or phenoxy, which is unsubstituted or substituted by one or more C ₁ -C ₆ alkyl or halogen;

;R ₇₁ represents phenyl, naphthyl, benzoyl or naphthoyl, each of which is substituted with one or more halogen, C ₁ -C ₁₂ alkyl, C ₃ -C ₈ cycloalkyl, benzyl, phenoxycarbonyl, C ₂ -C ₁₂ alkoxycarbonyl, OR ₇₃ , SR ₇₄ , SOR ₇₄ , SO ₂ R ₇₄ or NR ₇₅ R ₇₆ , where the substituents OR ₇₃ , SR ₇₄ and NR ₇₅ R ₇₆ optionally form 5- or 6-membered rings by radicals R ₇₃ , R ₇₄ , R ₇₅ and / or R ₇₆ with additional substituents on the phenyl or naphthyl ring; or each of which is substituted phenyl or phenyl which is substituted by one or more OR ₇₃ , SR ₇₄ or NR ₇₅ R ₆₆ ; or R ₇₁ is thioxanthyl or

;

R ₇₂ is hydrogen, unsubstituted C ₁ -C ₂₀ alkyl or C ₁ -C ₂₀ alkyl, which is substituted with one or more halogen, OR ₇₃ , SR ₇₄ , C ₃ -C ₈ cycloalkyl or phenyl; or is C ₃ -C ₈ cycloalkyl; or represents phenyl, which is unsubstituted or substituted by one or more C ₁ -C ₆ alkyl, phenyl, halogen, OR ₇₃ , SR ₇₄ or NR ₇₅ R ₇₆ ; or is C ₂ -C ₂₀ alkanoyl or benzoyl, which is unsubstituted or substituted with one or more C ₁ -C ₆ alkyl, phenyl, OR ₇₃ , SR ₇₄ or NR ₇₅ R ₇₆ ; or represents C ₂ -C ₁₂ alkoxycarbonyl, phenoxycarbonyl, CN, CONR ₇₅ R ₇₆ , NO ₂ , C ₁ -C ₄ haloalkyl, S (O) _y —C ₁ -C ₆ alkyl or S (O) _y- phenyl,

y is 1 or 2;

Y ₂ is a direct bond or is not a bond;

;Y ₃ represents NO ₂ or

;

;R ₇₃ and R ₇₄ independently of one another are hydrogen, C ₁ -C ₂₀ alkyl, C ₂ -C ₁₂ alkenyl, C ₃ -C ₈ cycloalkyl, C ₃ -C ₈ cycloalkyl, which is dangling one or more, preferably 2 , O, phenyl-C ₁ -C ₃ alkyl; or are C ₁ -C ₈ alkyl which is substituted by OH, SH, CN, C ₁ -C ₈ alkoxy, C ₁ -C ₈ alkanoyl, C ₃ -C ₈ cycloalkyl, C ₃ -C ₈ cycloalkyl, which is dangling one or more O or C ₁ -C ₈ alkyl of which is substituted by benzoyl which is unsubstituted or substituted by one or more C ₁ -C _{6 of} alkyl, halogen, OH, C ₁ -C ₄ alkoxy or C ₁ -C ₄ alkylsulfanyl; or are phenyl or naphthyl, each of which is unsubstituted or substituted by halogen, C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ alkoxy, phenyl-C ₁ -C ₃ alkoxy, phenoxy, C ₁ -C ₁₂ alkylsulfanyl, phenylsulfanyl, N (C ₁ -C ₁₂ alkyl) ₂ , diphenylamino or

;

R ₇₅ and R _{76 are} independently hydrogen, C ₁ -C ₂₀ alkyl, C ₂ -C ₄ hydroxyalkyl, C ₂ -C ₁₀ alkoxyalkyl, C ₂ -C ₅ alkenyl, C ₃ -C ₈ cycloalkyl, phenyl- C ₁ -C ₃ alkyl, C ₁ -C ₈ alkanoyl, C ₃ -C ₁₂ alkenoyl, benzoyl; or are phenyl or naphthyl, each of which is unsubstituted or substituted with C ₁ -C ₁₂ alkyl, benzoyl or C ₁ -C ₁₂ alkoxy; or R ₇₅ and R ₇₆ together represent C ₂ -C ₆ alkylene, optionally dangling O or NR ₇₃ and optionally substituted with hydroxyl, C ₁ -C ₄ alkoxy, C ₂ -C ₄ alkanoyloxy or benzoyloxy;

R ₇₇ is C ₁ -C ₁₂ alkyl, thienyl or phenyl, which is unsubstituted or substituted with C ₁ -C ₁₂ alkyl, OR ₇₃ , morpholino or N-carbazolyl.

Specific examples are 1,2-octanedione-1- [4- (phenylthio) phenyl] -2- (O-benzoyloxime) (Irgacure ^® OXE01), standard-1- [9-ethyl-6- (2-methylbenzoyl) - 9H-carbazol-3-yl] -1- (O-acetyloxy) (Irgacure ^® OXE02), 9H-thioxanthen-2-carboxaldehyde-9-oxo-2- (O-acetyloxy), ethanone-1- [9-ethyl -6- (4-morpholinobenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), ethanone-1- [9-ethyl-6- (2-methyl-4- (2- (1, 3-dioxo-2-dimethyl-cyclopent-5-yl) ethoxy) benzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxy) (Adeka N-1919), ethanone-1- [9- ethyl 6-nitro-9H-carbazol-3-yl] -1- [2-methyl-4- (1-methyl-2-methoxy) ethoxy) phenyl] -1- (O-acetyloxy) (Adeka NCI831), etc.

It is also possible to add cationic photoinitiators, such as benzoyl peroxide (other suitable peroxides are described in US 4950581, column 19, lines 17-25), or aromatic salts of sulfonium, phosphonium or iodonium, such as described, for example, in US 4950581, column 18 , line 60 to column 19, line 10.

Suitable sulfonium salt compounds are compounds of the formula XVa, XVb, XVc, XVd or XVe

in which

или

R ₈₀ , R ₈₁ and R ₈₂ are each independently unsubstituted phenyl or phenyl substituted with -S-phenyl,

or

R ₈₃ is a direct bond, S, O, CH ₂ , (CH ₂ ) ₂ , CO or NR ₈₉ ;

R ₈₄ , R ₈₅ , R ₈₆ and R ₈₇ independently represent hydrogen, C ₁ -C ₂₀ alkyl, C ₃ -C ₈ cycloalkyl, C ₁ -C ₂₀ alkoxy, C ₂ -C ₂₀ alkenyl, CN, OH , halogen, C ₁ -C ₆ alkylthio, phenyl, naphthyl, phenyl-C ₁ -C ₇ alkyl, naphthyl-C ₁ -C ₃ alkyl, phenoxy, naphthyloxy, phenyl-C ₁ -C ₇ alkyloxy, naphthyl-C ₁ - C ₃ alkyloxy, phenyl-C ₂ -C ₆ alkenyl, naphthyl-C ₂ -C ₄ alkenyl, S-phenyl, (CO) R ₈₉ , O (CO) R ₈₉ , (CO) OR ₈₉ , SO ₂ R ₈₉ or OSO ₂ R ₈₉ ;

,R ₈₈ represents C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ hydroxyalkyl,

,

или

or

R ₈₉ represents hydrogen, C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ hydroxyalkyl, phenyl, naphthyl or biphenylyl;

R ₉₀ , R ₉₁ , R ₉₂ and R ₉₃ independently of one another have one of the meanings as given for R ₈₄ ; or R ₉₀ and R _{91 are} combined to form an articulated ring system with the benzene rings to which they are attached;

R ₉₅ is a direct bond, S, O or CH ₂ ;

R ₉₆ represents hydrogen, C ₁ -C ₂₀ alkyl; C ₂ -C ₂₀ alkyl, which is terminated by one or more O; or is —LMR ₉₈ or —LR ₉₈ ;

R ₉₇ has one of the meanings given for R ₉₆ or represents

R ₉₈ is a monovalent fragment of a sensitizer or photoinitiator;

Ar ₁ and Ar ₂ independently of one another are phenyl unsubstituted or substituted with C ₁ -C ₂₀ alkyl, halogen or OR ₉₉ ;

or are unsubstituted naphthyl, antryl, phenanthryl or biphenylyl;

or are naphthyl, antryl, phenanthryl or biphenylyl substituted with C ₁ -C ₂₀ alkyl, OH or OR ₉₉ ;

:or are —Ar ₄ —A ₁ —Ar ₃ or

:

Ar ₃ is unsubstituted phenyl, naphthyl, antryl, phenanthryl or biphenylyl;

or represents phenyl, naphthyl, antryl, phenanthryl or biphenylyl substituted with C ₁ -C ₂₀ alkyl, OR ₉₉ or benzoyl;

Ar ₄ represents phenylene, naphthylene, antrylene or phenanthylene;

A ₁ is a direct bond, S, O or C ₁ -C ₂₀ alkylene;

X is CO, C (O) O, OS (O), O, S or NR ₉₉ ;

L is a direct bond, S, O, C ₁ -C ₂₀ alkylene or C ₂ -C ₂₀ alkylene, which are terminated by one or more non-sequential O;

R ₉₉ represents C ₁ -C ₂₀ alkyl or C ₁ -C ₂₀ hydroxyalkyl; or is C ₁ -C ₂₀ alkyl substituted with O (CO) R ₁₀₂ ;

M ₁ represents S, CO or NR ₁₀₀ ;

M ₂ represents a direct bond, CH ₂ , O or S;

R ₁₀₀ and R ₁₀₁ independently of one another are hydrogen, halogen, C ₁ -C ₈ alkyl, C ₁ -C ₈ alkoxy or phenyl;

R ₁₀₂ represents a C ₁ -C ₂₀ alkyl;

иR ₁₀₃ represents

and

, CH₃-SO₃, СlO₄, PO₄, NO₃, SO₄, CH₃-SO₄, или

.E is an anion, especially PF ₆ , SbF ₆ , AsF ₆ , BF ₄ , (C ₆ F ₅ ) B, Cl, Br, HSO ₄ , CF ₃ —SO ₃ , F-SO ₃ ,

, CH ₃ —SO ₃ , ClO ₄ , PO ₄ , NO ₃ , SO ₄ , CH ₃ —SO ₄ , or

.

Specific examples of the sulfonium salt compounds are, for example, Irgacure ^® 270 (BASF SE); Cyracure ^® UV1-6990, Sugashige ^® UV1-6974 (Union Carbide), Degacure ^® KI 85 (Degussa), SP-55, SP-150, SP-170 (Asahi Denka), GE UFE 1014 (General Electric), SarCat ^® KI-85 (= triarylsulfonium hexafluorophosphate; Sartomer), SarCat ^® CD 1010 (= mixed triarylsulfonium hexafluoroantimonate; Sartomer); SarCat ^® CD 1011 (= mixed triarylsulfonium hexafluorophosphate; Sartomer),

Suitable compounds of iodonium salts are compounds of formula XVI

в которой

wherein

, CH₃-SO₃, СlO₄, PO₄, NO₃, SO₄, СН₃-SO₄ или

.R ₁₁₀ and R _{111 are} each independently hydrogen, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkoxy, OH-substituted C ₁ -C ₂₀ alkoxy, halogen, C ₂ -C ₁₂ alkenyl, C ₃ -C ₈ cycloalkyl, especially methyl, isopropyl or isobutyl; and E is an anion, especially PF ₆ , ShF ₆ , AsF ₆ , BF ₄ , (C ₆ F ₅ ) ₄ V, Cl, Br, HSO ₄ , CF ₃ —SO ₃ , F-SO ₃ ,

, CH ₃ —SO ₃ , ClO ₄ , PO ₄ , NO ₃ , SO ₄ , CH ₃ —SO ₄ or

.

Specific examples of the iodonium salt compounds include, for example, tetrakis (pentafluorophenyl) borate tolilkumiliodoniya, hexafluoroantimonate or hexafluorophosphate, 4 - [(2-hydroxy-tetradecyloxy) -phenyl] phenyliodonium hexafluorophosphate tolilkumiliodoniya hexafluorophosphate, 4-isopropylphenyl-4'-metilfeniliodoniya hexafluorophosphate, 4-isobutylphenyl -4'-metilfeniliodoniya (Irgacure ^® 250, BASF SE), hexafluorophosphate or hexafluoroantimonate, 4-octyloxyphenyl-feniliniodoniya, hexafluoroantimonate or hexafluorophosphate, bis (dodecylphenyl) iodonium hexafluorophosphate, bis (4-methylphenyl) UQ donium, bis (4-methoxyphenyl) iodonium hexafluorophosphate, 4-methylphenyl-4-ethoxyphenyl iodonium hexafluorophosphate, 4-methylphenyl-4'-dodecylphenyliodonium hexafluorophosphate, 4-methylphenyl-4'-phenoxyphenyliodonium hexafluorophosphate.

Of all the iodonium salts mentioned, of course, compounds with other anions are also suitable. The preparation of iodonium salts is known to those skilled in the art and is described in the literature, for example, US 4151175, US 3862333, US 4694029, EP 562897, US 4399071, US 6306555, WO 98/46647 J.V. Crivello, "Photoinitiated Cationic Polymerization" in UV Curing: Science and Technology, Editor S.P. Pappas, pp. 24-77, Technology Marketing Corporation, Norwalk, Conn. 1980, ISBN No. 0-686-23773-0; J.V. Crivello, J.H.W. Lam, Macromolecules, 10, 1307 (1977) and J.V. Crivello, Ann. Rev. Mater. Sci. 1983, 13, pp. 173-190 and J.V. Crivello, Journal of Polymer Science, Part A: Polymer Chemistry, T. 37, 4241-4254 (1999).

Halogen is fluoro, chloro, bromo and iodo.

C ₁ -C ₂₄ alkyl (C ₁ -C ₂₀ alkyl, especially C ₁ -C ₁₂ alkyl) is generally linear or branched whenever possible. Examples are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethylpropyl, 1,1,3, 3-tetramethylpentyl, n-hexyl, 1-methylhexyl, 1,1,3,3,5,5-hexamethylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 1,1,3,3-tetramethylbutyl and 2-ethylhexyl, n-nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl or octadecyl. C ₁ -C ₈ alkyl is mainly methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2- dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 1,1,3,3-gtetramethylbutyl and 2-ethylhexyl. C ₁ -C ₄ alkyl is mainly methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl.

C ₂ -C ₁₂ alkenyl (C ₂ -C ₅ alkenyl) groups are straight-chain or branched alkenyl groups, such as, for example, vinyl, allyl, metall, isopropenyl, 2-butenyl, 3-butenyl, isobutenyl, n-penta-2 , 4-dienyl, 3-methyl-but-2-enyl, n-oct-2-enyl or n-dodec-2-enyl.

C ₁ -C ₁₂ alkoxy groups (C ₁ -C ₈ alkoxy groups) are straight-chain or branched alkoxy groups, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, amyloxy, isoamyloxy or tert- amyloxy, heptyloxy, octyloxy, isooctyloxy, nonyloxy, decyloxy, undecyloxy and dodecyloxy.

C ₁ -C ₁₂ alkylthio groups (C ₁ -C ₈ alkylthio groups) are straight-chained or branched alkylthio groups and have the same preferences as alkoxy groups, except that oxygen is replaced by sulfur.

C ₁ -C ₁₂ alkylene is a divalent C ₁ -C ₁₂ alkylene, i.e. alkyl having two (instead of one) free valencies, for example, trimethylene or tetramethylene.

The cycloalkyl group is mainly C ₃ -C ₈ cycloalkyl, such as, for example, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl, which may be unsubstituted or substituted.

In some cases, predominantly, in addition to the photoinitiator, use a sensitizer compound. Examples of suitable sensitizer compounds are disclosed in WO 06/008251, from page 36, line 30 to page 38, line 8, the disclosures of which are incorporated herein by reference. As a sensitizer, in particular, benzophenone compounds described above can be used.

The lamp used in the method and the apparatus according to the present invention has a peak (s) of emission in the UV-A range (400 nm to 320 nm) and a short-wavelength visible spectrum (400-450 nm). That is, the lamp has a peak (peaks) of emission in the range from 320 to 450 nm.

UV radiation is usually classified as UV-A, UV-B and UV-C, as follows: UV-A: 400 nm to 320 nm, UV-B: 320 nm to 290 nm, UV-C: 290 nm up to 100 nm.

In the case of using a transparent substrate, the type of lamp, as a rule, is not critical. For example, high or medium pressure mercury lamps are sufficient.

As the radiation source, any ultraviolet light source can be used, such as a high or low pressure mercury lamp, a cold cathode tube, black radiation, an ultraviolet LED, an ultraviolet laser, and a flashlight.

Examples of lamps that can be used in the process according to the present invention are shown below:

- discharges in medium-pressure mercury vapor are modified by implication of metal halides in small fractions to change the spectral capacitance:

- doped with iron - spectral capacitance shifted to 350-450 nm;

- doped with gallium - emits very little UV; radiation in the violet and blue spectral regions (expected additional UV lines by doping the discharge in mercury vapor with metal iodides at a wavelength / nm: Gallium (Ga) 403, 417 and Iron (Fe) 358, 372, 374/5, 382, 386, 388); and

- Focused Reflected Diode Array (FRDA) systems (igb-tech GmbH), such as, for example, FRDA 202, having an emission peak of about 400 nm. Multiple-spectrum lamps can also be used.

Advantageously, a medium pressure mercury arc doped with gallium or iron is used in the method and apparatus according to the present invention to obtain more efficient UV-A (315-400 nm) or UV-B (280-315 nm) and to provide better intervals for the efficiency of the radiation source and more high degree of cure.

Each emitter consists of an aluminum casing containing a linear reflector with an elliptical (or, depending on the application, parabolic) cross-section. The reflector attached to the emitter housing is made of special aluminum, which has a high degree of UV reflectivity and resistance to oxidation and corrosion.

The used photoinitiator (photoinitiators) or a mixture of photoinitiators and a lamp should be optimized depending on the particular type of substrate to achieve optimal printing speed.

The formation of an optically variable image on a substrate includes the deposition of a curable composition on at least a portion of the substrate. A composition, typically an ink or varnish-based coating, can be delayed by engraving, flexographic, inkjet, offset and screen printing, as well as coating processes. In experiments on a laboratory scale, level reduction with a wire blank or a doctor blade is suitable.

Depending on the amount of solvent in the varnish and depending on the printing process, different dry coating thicknesses are obtained. The mass ratio of pigment based on silver nanoscale to a binder affects the resulting color in transmittance and reflection. Theoretically, the ratio of pigment to binder, as given below, leads to a schematic thickness of the dry coating.

A coating thickness between 0.2 and 4 microns is typical of the method according to the present invention.

Basically, the mass ratio of pigment based on silver nanoscale to a binder is from 5: 1 to 1: 1000.

Curable varnish is cured with ultraviolet (UV) light. UV curable varnishes are commercial products and can be obtained, for example, from BASF SE. The actinic radiation varnishes used in the present invention are required to achieve a thickened state when they are separated from the image pad in order to hold the image on the upper layer of a submicroscopic, holographic image or pattern (OVI). Particularly suitable for varnish compositions are chemicals used in radiation curable industries in industrial coatings and printing. Particularly suitable are compositions containing one or more photolatent catalysts that will initiate the polymerization of the UV-exposed varnish layers. Particularly suitable for rapid solidification and solidification are compositions containing one or more monomers and oligomers sensitive to free radical polymerization, such as acrylates, methacrylates or monomers and / or oligomers containing at least one ethylenically unsaturated group.

Unsaturated compounds may include one or more olefinic double bonds. They can be low (monomeric) or high (oligomeric) molecular weight. Examples of monomers containing a double bond are alkyl, hydroxyalkyl or aminoacrylates, or alkyl, hydroxyalkyl or aminomethacrylates, for example methyl, ethyl, butyl, 2-ethylhexyl or 2-hydroxyethyl acrylate, isobornyl acrylate, methyl methacrylate or ethyl methacrylate. Silicon acrylates are also beneficial. Other examples are acrylonitrile, acrylamide, methacrylamide, N-substituted (meth) acrylamides, vinyl esters such as vinyl acetate, vinyl ethers such as isobutyl vinyl ether, styrene, alkyl and halostyrenes, N-vinyl pyrrolidone, vinyl chloride or vinyl chloride. Examples of monomers containing two or more double bonds are ethylene glycol, propylene glycol, neopentyl glycol, hexamethylene glycol or bisphenol A diacrylates, and 4,4'-bis (2-acryl-hydroxyethoxy) diphenylpropane, trimethylolpropane triacrylate triacrylate triacrylate triacrylate, triacrylate divinylbenzene, divinyl succinate, diallyl phthalate, triallyl phosphate, triallyl isocyanurate or tris (2-acryloyl ethyl) isocyanurate.

Examples of polyunsaturated compounds of relatively high molecular weight (oligomers) are acrylic modified epoxy resins, polyesters containing acrylate groups, epoxy groups and vinyl ether groups, as well as polyurethanes and polyethers. Further examples of unsaturated oligomers are polyester unsaturated resins, which are usually derived from maleic acid, phthalic acid and one or more diols and have molecular weights of from about 500 to 3000. It is also possible to use vinyl ether monomers and oligomers, and also maleate-terminated oligomers with backbones of polyester, polyurethane, polyester, polyvinyl ether and epoxy. Particularly suitable are combinations of oligomers that carry vinyl ether groups and polymers as described in WO 90/01512. However, copolymers of vinyl ether and maleic acid functional monomers are also suitable. Unsaturated oligomers of this type may also be referred to as prepolymers.

Particularly suitable examples are esters of ethylenically unsaturated carboxylic acids and polyols or polyepoxides, and polymers containing ethylenically unsaturated groups in the chain or in side groups, for example, unsaturated polyesters, polyamides and polyurethanes and their copolymers, polymers and copolymers containing (meth) acrylic groups in the side chains, as well as mixtures of one or more similar polymers.

Examples of unsaturated carboxylic acids are acrylic acid, methacrylic acid, crotonic acid, itaconic acid, cinnamic acid, and unsaturated fatty acids such as linolenic acid or oleic acid. Acrylic and methacrylic acid are preferred.

Suitable polyols are aromatic and, in particular, aliphatic and cycloaliphatic polyols. Examples of aromatic polyols are hydroquinone, 4,4'-dihydroxydiphenyl, 2,2-di (4-hydroxyphenyl) propane, as well as novolaks and resols. Examples of polyepoxides are compounds based on the above polyols, especially aromatic polyols, and epichlorohydrin. Other suitable polyols are polymers and copolymers containing hydroxyl groups in the polymer chain or in side groups, examples being polyvinyl alcohol and its copolymers or polyhydroalkyl methacrylates or copolymers thereof. Additional polyols that are suitable are oligoesters containing hydroxyl end groups. Examples of aliphatic and cycloaliphatic polyols are alkylenediols containing preferably from 2 to 12 carbon atoms, such as ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol, hexanediol, octanediol, dodecanediol, diethylene glycol, triethylene glycol, polyethylene glycols having a molecular weight of preferably from 200 to 1500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,4-dihydroxymethylcyclohexane, glycerol trisf-hydroxyethyl) amine, trimethylol ethane, trimethylol propane, pentaerythritol, dipentaerythritol and co rbit.

The polyols can be partially or fully esterified with one carboxylic acid or with various unsaturated carboxylic acids, and in partial esters the free hydroxyl groups can be modified, for example, esterified (converted to ether or ester) with other carboxylic acids.

Examples of esters are: trimethylolpropane triacrylate, trimethylolethane triacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, tetrametilenglikoldimetakrilat, triethylene glycol dimethacrylate, tetraetilenglikoldiakrilat, pentaeritritdiakrilat, pentaerythritol triacrylate, pentaeritrittetraakrilat, dipentaeritritdiakrilat, dipentaeritrittriakrilat, dipentaeritrittetraakrilat, dipentaeritritpentaakrilat, dipentaeritritgeksaakrilat, tripentaeritritoktaakrilat, pentaeritritdimetakrilat, pentaerythritol tri methacrylate, dipentaeritritdimetakrilat, dipentaeritrittetrametakrilat, tripentaeritritoktametakrilat, pentaeritritdiitakonat, dipentaeritrittris-itaconate, dipentaeritritpentaitakonat, dipentaeritritgeksaitakonat, ethylene glycol diacrylate, 1,3-butane dioldiakrilat, 1,3-butanediol dimethacrylate, 1,4-butandioldiitakonat, sorbittriakrilat, sorbittetraakrilat, modifitsirovannyy- pentaerythritol triacrylate, sorbittetrametakrilat, sorbitol pentaacrylate, sorbitol hexaacrylate, acrylates and methacrylates of oligoesters, diacrylate and triacrylate glyce ina, 1,4-cyclohexane diacrylate, bisacrylates and bismethacrylates of polyethylene glycol having a molecular weight of from 200 to 1500, or mixtures thereof.

Amides of identical or different unsaturated carboxylic acids with aromatic, cycloaliphatic and aliphatic polyamines containing preferably from 2 to 6, especially from 2 to 4 amino groups, are also suitable as polymerizable components. Examples of such polyamines are ethylenediamine, 1,2- or 1,3-propylenediamine, 1,2-, 1,3-or 1,4-butylenediamine, 1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine, dodecylenediamine, 1 , 4-diaminocyclohexane, isophorondiamine, phenylenediamine, bisphenylenediamine, di-β-aminoethyl ether, diethylenetriamine, triethylenetetraamine, di (β-aminoethoxy) - or di (β-aminopropoxy) ethane. Other suitable polyamines are polymers and copolymers, preferably with additional amino groups in the side chain, and oligoamides having terminal amino groups. Examples of such unsaturated amides are methylene bisacrylamide, 1,6-hexamethylene bisacrylamide, diethylenetriamine trismethacrylamide, bis (methacrylamidopropoxy) ethane, β-methacrylamidoethyl methacrylate and Ν [(β-hydroxyethoxy) ethyl] acrylamide.

Suitable unsaturated polyesters and polyamides are derived, for example, from maleic acid and from diols or diamines. Some of the maleic acid can be replaced with other dicarboxylic acids. They can be used together with ethylenically unsaturated comonomers, for example styrene. Polyesters and polyamides can also be derived from dicarboxylic acids and from ethylenically unsaturated diols or diamines, especially with relatively long chains, for example, from 6 to 20 carbon atoms. Examples of polyurethanes are polyurethanes consisting of saturated or unsaturated diisocyanates and unsaturated or respectively saturated diols.

Polymers with (meth) acrylate groups in the side chain are also known. They can be, for example, products of the interaction of novolac-based epoxies with (meth) acrylic acid, or they can be homo- or copolymers of vinyl alcohol or their hydroxyalkyl derivatives, which are esterified with (meth) acrylic acid, or they can be homo- and copolymers (meth) acrylates, which are esterified hydroxyalkyl (meth) acrylates.

Other suitable polymers with acrylate or methacrylate groups in the side chains are, for example, solvent-soluble or alkali-soluble polyimide starting materials, for example, amine acid polyester compounds containing photopolymerizable side groups or attached to the skeleton or to the ester groups in the molecule, t .e. according to EP 624826. Such oligomers or polymers can be formulated with optional reaction diluents like multifunctional (meth) acrylates to produce highly sensitive polyimide starting materials.

Examples of polymerizable components are also polymers or oligomers containing at least two ethylenically unsaturated groups and at least one carboxy function within the molecular structure, such as a resin obtained by reacting a saturated or unsaturated polybasic anhydride with the product of the reaction of an epoxy compound and an unsaturated monocarboxylic acid, for example photosensitive compounds, as described in JP 10-301276, and commercial products, such as, for example, EB 9696, UCB Chemicals; KAYARAD TCR1025, Nippon Kayaku Co., LTD., NK OLIGO EA-6340, EA-7440 from Shin-Nakamura Chemical Co., Ltd., or an addition product formed between a carboxyl group-containing resin and an unsaturated compound containing α, β- unsaturated double bond and epoxy group (e.g., ASA200M, Daicel Industries, Ltd.). Additional commercial products as examples of a polymerizable component are ACA200, ACA210P, ACA230AA, ACA250, ACA300, ACA320 from Daicel Chemical Industries, Ltd.

Photopolymerizable compounds are used alone or in any desired mixtures. Mixtures of (meth) acrylates of polyols are preferably used. A preferred composition contains at least one compound containing at least one free carboxyl group.

As a diluent, a mono- and multifunctional ethylenically unsaturated compound or mixtures of several of these compounds up to 70 wt.% Can be included in the above composition. % based on the solid phase of the composition.

The invention also provides compositions containing, as a polymerizable component, at least one ethylenically unsaturated photopolymerizable compound that is emulsified or soluble in water or organic solvents.

Unsaturated polymerizable components can also be used in admixture with non-photopolymerizable film-forming components. They can be, for example, physically dried polymers or their solutions in organic solvents, for example, nitrocellulose or cellulose acetate butyrate. However, they can also be chemically and / or thermally curable (thermoset) resins, examples being polyisocyanates, polyepoxides and melamine-based resins, as well as polyimide sources. The use of thermosetting resins at the same time is important for applications in systems known as hybrid systems, which are photopolymerized in the first step and crosslinked in the second step by thermal post-treatment.

The polymerizable compositions may further comprise a solvent. The solvent may be a mixture of esters and alcohols, and preferably normal propyl acetate and ethanol. More preferably, the mixture of ester and alcohol is in a ratio between 10: 1 and 40: 1, even more preferably from 20: 1 to 30: 1. The solvent used may contain any one or more esters, such as n-propyl acetate, isopropyl acetate, ethyl acetate, butyl acetate; an alcohol such as ethyl alcohol, industrial methylated solvents, isopropyl alcohol or normal propyl alcohol; a ketone such as methyl ethyl ketone or acetone; an aromatic hydrocarbon such as toluene, and water.

Although only water can be used as a diluent, in most cases it is used together with an organic solvent such as alcohol.

To initiate the curing process using UV radiation, a photoinitiator or a mixture of photoinitiators is introduced into the composition / composition.

In a specific embodiment, the curable composition comprises

(a) from 5.0 to 0.6, especially from 5.0 to 1.0, very especially from 4.0 to 2.5 wt. % photoinitiator

(b) from 94.9 to 11.9, especially from 94.1 to 19.0, very especially from 76.0 to 47.5 wt. % of one or more ethylenically unsaturated resins, monomers or mixtures thereof,

(c) from 0.1 to 87.5, especially from 1.0 to 80.0, very especially from 20.0 to 50.0 wt. % metal pigment, which is in the form of plate-shaped particles of transition metals, as defined above

in which the sum of the components from a) to c) is reduced to 100%.

Typically, the photoinitiator is mainly added in an amount of from 1% to 20%, preferably from 3% to 10 wt. % based on the weight of the entire curable composition.

The curable composition may contain various additives. Examples thereof include thermal inhibitors, light stabilizers, optical brighteners, fillers and pigments, as well as white and colored pigments, dyes, antistatic additives, adhesion promoters, wetting agents, flow agents, lubricants, waxes, anti-adhesives, dispersants, emulsifiers, antioxidants fillers, for example, talc, gypsum, silicic acid, rutile, carbon black, zinc oxide, iron oxides, reaction accelerators, thickeners, matting agents, antifoam agents, leveling agents and others activators, common, for example, in the technology of varnishes, inks and coatings.

UV varnish may contain epoxy acrylate from the CRAYNOR® Sartomer Europe series, or the LAROMER® series, available from BASF SE (10 to 60%) and one or more acrylates (single or multi-functional), the monomers of which are available from Sartomer Europe, or BASF SE ( 20 to 90%) and one or more photoinitiators (1 to 15%), such as Irgacure® 819 (BASF SE) and an equalizer such as BYK®361 (0.01 to 1%) from BYK Chemie.

In a further embodiment of the present invention, the ultraviolet coating may be colored. That is, the curable composition may contain pigments and / or dyes. The pigments may be transparent organic coloring pigments or inorganic pigments.

Suitable colored pigments especially include organic pigments selected from the group consisting of pigments of azo, azomethine, methine, anthraquinone, phthalocyanine, perinone, perylene, diketopyrrolopyrrole, thioindigo, dioksaziniminoizoindolina, dioxazine, iminoizoindolinona, quinacridone flavantrona, indatrona, anthrapyrimidine and quinophthalone or mixtures thereof or a solid solution thereof, especially the pigment dioxazine, diketopyrrolopyrrole, quinacridone, phthalocyanine, indatron or iminoisoindolinone, or a mixture thereof or their solid solution.

Of particular interest are colored organic pigments, including C.I. Pigment Red 202, C.I. Pigment Red 122, C.I. Pigment Red 179, C.I. Pigment Red 170, C.I. Pigment Red 144, C.I. Pigment Red 177, C.I. Pigment Red 254, C.I. Pigment Red 255, C.I. Pigment Red 264, C.I. Pigment Brown 23, C.I. Pigment Yellow 109, C.I. Pigment Yellow 110, C.I. Pigment Yellow 147, C.I. Pigment Orange 61, C.I. Pigment Orange 71, C.I. Pigment Orange 73, C.I. Pigment Orange 48, C.I. Pigment Orange 49, C.I. Pigment Blue 15, C.I. Pigment Blue 60, C.I. Pigment Violet 23, C.I. Pigment Violet 37, C.I. Pigment Violet 19, C.I. Pigment Green 7, C.I. Pigment Green 36, 2,9-dichloroquinacridone in plate form, described in WO 08/055807, or mixtures thereof or their solid solution.

As an additional component, lamellar organic pigments such as quinacridones, phthalocyanine, fluororubin, dioxazines, red perylene or lamellar pyrrolopyrroles can advantageously be used.

Suitable colored pigments also include traditional inorganic pigments, especially those selected from the group consisting of metal oxides, yellow antimony, lead chromate, lead chromate, molybdate lead, ultramarine blue, cobalt blue, manganese blue, green chromium oxide, green hydrogenated oxide chromium, cobalt greens and metal sulfides such as cerium or cadmium sulfide, cadmium sulfoselenides, zinc ferrite, bismuth vanadate, Prussian blue, Fe ₃ O ₄ , carbon black and mixed metal oxides. Examples of commercially available inorganic pigments are BAYFERROX® 3920, BAYFERROX® 920, BAYFERROX® 645T, BAYFERROX® 303T, BAYFERROX® 110, BAYFERROX® PO M, CHROMOXIDGRUEN GN and CHROMOXIDGRUEN GN-M.

Examples of dyes that can be used to color a curable composition are selected from the group consisting of azo, azomethine, methine, anthraquinone, phthalocyanine, dioxazine, flavantrone, indatron, anthrapyrimidine and metallic complex dyes. Preferred are monoazo dyes, cobalt-based complex dyes, chromium-based complex dyes, anthraquinone-based dyes and copper phthalocyanine dyes.

According to a further aspect of the invention, nano- and microstructures are capable of being printed using conventional printing methods, thereby enabling printing at high speeds, at the required width, and in register with any conventional printing on the printed document or label.

Optical microstructured images consist of a series of structured surfaces (surface relief microstructures).

These surfaces can have straight or curved contours, with a constant or statistical arrangement, and can even vary in size from nanometers to millimeters. Drawings can be round, linear or not have a uniform pattern. Embossed patterns may contain microstructures having sizes ranging from about 0.01 microns to about 100 microns. Light interference patterns are based on microstructures having sizes ranging from about 0.1 microns to about 10 microns, preferably from about 0.1 microns to about 1 micron. For example, a Fresnel lens has a microstructured surface on one side and a flat surface on the other. The microstructured surface consists of a series of grooves with varying angles of inclination, as the distance from the optical axis increases. Designed chamfers located between inclined chamfers usually do not affect the optical characteristics of the Fresnel lens.

The optical interference pattern can take various traditional forms, including diffraction patterns, such as diffraction gratings, patterns of refracted waves, holographic patterns, such as two-dimensional and three-dimensional holographic images, a cubic corner reflector, Kinegram® devices (i.e., holograms with variable images, as the angle of view is changing), Pixelgram® devices (i.e. a hologram with numerous holographic image elements located in a spatial orientation that generates a single holographic image), zero-order diffraction patterns, moiré patterns or other patterns of light interference based on microstructures having sizes ranging from about 0.1 microns to about 10 microns, preferably from about 0.1 microns to about 1 microns, and various combinations of the foregoing, such as holograms / lattice images, or other similar interference patterns.

Such structures include, but are not limited to: (1) electron-generated holograms; (2) holograms of point matrices; (3) computer generated holograms; (4) optically variable devices (OPU); (5) diffractive optical variable devices (DOVID); (6) lenses, in particular microlenses; (7) biconvex lenses; (8) non-reflective structures; (9) artificial lighting structures; (10) deep structures (for example, structures that refract only one wavelength at a very wide viewing angle, such as that found in some butterflies and other insects); (11) radio frequency identification (RFID) antennas; (12) embossable computer integrated circuits; (13) patterns of direct back reflection; (14) metal-like structures; ROVIDs (reflective optically variable devices).

An optically variable device (OPU) is, for example, a diffractive optically variable image (DOV1). The term “diffractive optically variable image” as used herein may refer to any type of hologram, including but not limited to a multi-faceted hologram (eg, a two-dimensional hologram, a three-dimensional hologram, etc.), a stereogram, and a lattice image (for example , dot matrix, pixelgram, exgram, cinegram, etc.).

Basically, the metal in the curable composition is selected from the group consisting of Cu, Ag, Au, Zn, Cd, Ti, Cr, Μn, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt, preferably Ag and Cu .

Preferably, the particles comprise flakes of silver and / or copper. Particularly preferred is Ag.

Formed particles of transition metals have, for example, the largest edge lengths of 5 to 1000 nm and a thickness of 1 to 100 nm and contain hexagonal and / or triangular and / or truncated triangular prisms, moreover, prisms comprise more than 20% of the total formed transition metal particles.

In a specific embodiment of the present invention, platelet-shaped transition metal particles are used having the largest edge lengths from 15 nm to 1000 nm, preferably from 15 nm to 600 nm, and in particular from 20 nm to 500 nm, and a thickness from 2 nm to 100 nm , preferably from 2 to 40 nm, and in particular from 4 to 30 nm. The preparation of shaped transition metal particles is described, for example, in US 2008/0295646, WO 2004/089813, WO 2006/099312, C. Xue et al., Adv. Mater. 19, 2007, 4071, WO 2009056401 and WO 2010/108837. The use of platelet-shaped transition metal particles for producing holograms is described in WO 2011/064162.

Curable compositions contain a total number of molded particles of transition metals from 0.1 to 90 mass. %, preferably 1-20 mass. % based on total ink weight. The curable composition may further comprise a solvent. Typical solvents are already mentioned. For example, solvents may be mixtures of esters and alcohols, or preferably normal propyl acetate and ethanol. More preferably, the mixture of ester and alcohol is in a ratio between 10: 1 and 40: 1, even more preferably from 20: 1 to 30: 1. The solvent used in the curable composition may contain any one or more of esters, such as n-propyl acetate, isopropyl acetate, ethyl acetate, butyl acetate; alcohols such as ethyl alcohol, methanol, methoxypropanol, industrial methylated solvents, isopropyl alcohol or normal propyl alcohol; ketones such as cyclohexanone, methyl ethyl ketone or acetone; aromatic hydrocarbons such as toluene, and water.

Particles of (transition) metals of the plate form can be used in combination with spherical particles of (transition) metals, such as spherical particles of (transition) metals having a diameter of ≤40 nm, especially ≤20 nm.

In another embodiment, another metallic pigment may be added. A metallic pigment is a metallic pigment obtained by physical vapor deposition (PVD metallic pigment). The working range of deposition in vacuum can be in the range of 5 to 50 nm, the preferred thickness of the metal particles is in the range of 8 to 21 nm. Preferably, the particle thickness of the metallic pigment is less than 50 nm. More preferably, the thickness of the metal pigment particles is less than 35 nm. Even more preferably, the thickness of the metal pigment particles is less than 20 nm. Even more preferably, the thickness of the pigment particles is in the range of 5-18 nm.

In the case of using mixtures of such metal pigments, the ratio between the metal plate pigment and the binder system is from 10: 1 to 1: 1000.

The transparent or translucent substrate is selected from paper or from a thermoplastic or cross-linked polymer.

In relation to a thermoplastic or cross-linked polymer, a thermoplastic resin can be used, examples of which include polyethylene [polyethylene (PE), ethylene-vinyl acetate (EVA) copolymer, vinyl chloride-vinyl acetate copolymer, vinyl alcohol-vinyl acetate copolymer, polypropylene (PP) , vinyl-based polymers [polyvinyl chloride (PVC), polyvinyl butyral (PVB), polyvinyl alcohol (PVA), polyvinylidene chloride (PVdC), polyvinyl acetate (PVAc), polyvinyl formal (PVF)], polystyrene-based polymers [polystyrene polystyrene (PS) and acrylonitrile (AS), a copolymer of acrylonitrile, butadiene and styrene (ABS)], polymers based on acrylic acid [polymethylmethacrylate (PMMA), a copolymer of MMA and styrene], polycarbonate (PC), cellulose [ethyl cellulose (EC), cellulose acetate ( CA), propyl cellulose (CP), cellulose acetate butyrate (CAB), cellulose nitrate (CN)], fluorine-based polymers [polychlorofluoroethylene (PCTFE), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoroethylene copolymer (FEP), polyvinylidene fluoride] (PVd) , urethane-based polymers (PU), nylons [type 6, type 66, type 610, type 11], polyesters (alkyl ) [polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PCT)], phenolic resins such as novolacs or the like. In addition, thermosetting resins (cross-linked resins), such as resole type phenolic resin, urea resin, melamine resin, polyurethane resin, epoxy resin, unsaturated polyester and the like.

The paper backing can be a banknote, an identity document, such as a passport, an identification card, a driver’s license, packaging material, for example, a tag, a folding box, a paper bag for medicines, clothing, software, cosmetics, tobacco products or any other products that should be decorated or there is the possibility of falsification or falsification.

In a particular embodiment of the invention, the paper or paperboard is treated with a cationic polymer on the front side before applying the curable composition (varnish) to at least a portion of the front side of the paper substrate.

Processing in the context of the present invention includes all suitable means for applying a polymer solution to the surface of a paper substrate, in particular printing or coating.

Cationic polymers used in the present invention for paper processing include repeating amine units that are capable of forming cationic amine salts. The amine group-containing cationic polymer may be a homopolymer or copolymer. The homopolymer or copolymer may be either in the form of a base or partially or completely in the form of a cationic amine salt. Such cationic polymers are described, for example, in US 2008/0318150 on pages 3 to 4.

Preferably, the cationic polymer is polyvinylamine, which is preferably hydrolyzed to at least 90%.

Polyvinylamine or partially or fully hydrolyzed polyvinylformamide is obtained by polymerization of N-vinylformamide and subsequent hydrolysis and removal of formyl groups to give amine groups. The degree of hydrolysis can vary from 1% to 100%, preferably ≥50% and more preferably ≥90%. Particularly preferred is fully hydrolyzed polyvinylformamide.

Obtaining polymers based on N-vinylformamide and subsequent hydrolysis are described to a large extent, for example, in US 6132558, col. 2, line 36 to the count. 5, line 25. Polyvinylamine and partially or fully hydrolyzed polyvinylformamide are commercially available under the trade names Catiofast® and Polymin® from BASF SE.

For example, the average molecular weight of these polymers M _w is from 20,000 to 2,000,000 g / mol, for example, from 50,000 to 1,000,000, in particular from 100,000 to 500,000 g / mol.

For example, polyvinylamine contains from 0.1 to 22 milliequivalents (meq), for example, from 5 to 18 meq of cationic groups per gram of polyvinylamine. Polyvinylamine-based polymers are generally in the form of a dispersion or solution, for example, with a solids content of from 10% to 40%, for example, from 15% to 30% and preferably from 20% to 25%. They are usually applied to paper or paperboard from such solutions or dispersions.

The applied amount of the above polymer solution is, for example, from 2 to 20 g, for example, from 2 to 15 g and preferably from 4 to 12 g per m ^{2 of} paper substrate. The polymer solution is then dried by means of an infrared dryer and / or a hot air dryer.

It is also possible to apply additional natural polymers together with the cationic polymer, such as starch, in particular amylopectin. The amount mixed with the cationic polymer is generally from 5% to 50% based on the weight of the cationic polymer.

Preferably, the transparent or translucent substrate is selected from polyester, polyvinyl chloride (PVC), polyethylene, polycarbonate, polypropylene or polystyrene.

For example, the tool forming the microstructure of the surface topography is a gasket selected from the group consisting of a nickel sleeve, a nickel plate, a metal drum etched or formed by a laser, or other materials mounted on an opaque cylinder or a metal cylinder containing an optically variable device on the surface (OPA image )

In many cases, it is also possible to use a gasket that is made of a thermoplastic or thermosetting polymer.

Preferably, the gasket is a nickel plate mounted on an opaque cylinder or a metal cylinder and containing an image on the surface of the OPA.

The method outlined above can also be applied to already existing security elements, such as holograms. For example, when the transparent or translucent substrate already contains a security element, this security element can be additionally printed using the method of the present invention. The result is that depending on which side the security elements are viewed, one or the other is visible, which provides an additional step to prevent falsification or reproduction. This embodiment is illustrated in Example 4.

Another objective of the invention is a means of protection obtained using the method as defined above.

The resulting protective agent containing the microstructure of the surface topography can, for example, be printed with an additional colorless or slightly colored coating. The microstructure of the surface topography is still visible. The coating may be a conventional solvent-based coating or a UV curable coating. Examples of UV curable coating components are already given above. Examples of binders for solvent-bearing coatings are nitrocellulose, alkyd resins or polyacrylate resins. In the case of solvent-bearing coatings for evaporating the solvent, an additional step of drying by heating becomes necessary.

Preferably, the security measure includes banknotes, credit cards, identification documents such as passports, identification cards, driver’s licenses or other credentials, a paper bag for drugs, software, CDs, packaging for tobacco products or other products, or packaging for falsification or fake.

Another objective of the invention is the use of a protective agent, as defined above, to prevent falsification or reproduction, on a valuable, legal, identification document, security tag or product having a factory mark.

Another additional objective of the invention is a method of forming a coating exhibiting a color change depending on the angle on a transparent or translucent substrate, comprising the steps as defined above.

The coating shows a color change depending on the angle, i.e. color option as a function of viewing angle. A color change depending on the angle can be obtained with a pigment to binder ratio of 10: 1 to about 1: 100. The resulting color depends on the ratio of pigment to binder. Colors range from violet to blue in transmission and from silver to gold in reflection. Other colors can be observed at intermediate angles.

Preferably, the coating is deposited by intaglio printing.

The following examples illustrate the invention.

Getting Silver Plates

The preparation is carried out according to example 1 of WO 2011/064162. The precipitate is dispersed in any selected solvent, which includes water, methanol, ethyl acetate, cyclohexanone, methoxypropanol, to obtain a dispersion containing 20% silver plates.

Thus obtained plates are used in the following practical examples.

Practical examples

Photopolymer based materials:

Lumogen® OPU Primer 301 is a commercial UV curable product from BASF SE.

Irgacure® 2100 is a commercial photoinitiator from BASF SE.

The manufacture of a volume hologram (reflective hologram) is carried out according to WO 2005/124456 Example 1, page 22 or on a film from Bayer, Bayfol HX® or Dupont, Omnidex®, Toppan, DNP

The composition of UV varnish is shown below:

A mixture of photoinitiators

Bis (2,4,6-trimethylbenzoyl) oxide - 2,4,6-phenylphosphine trimethylbenzoyl-phenyl phosphinic acid ethyl ester

9 parts 91 parts

UV Ink Example 1

Preparation of UV ink: 1 g of UV varnish (Lumogen® OPU Primer 301 + 5% Irgacure® 2100) is added to 20 g of a dispersion of silver plates (20% pigment in methanol) in a 50 ml glass flask and gently stirred at room temperature. The resulting ink is coated with a wire preform 0 (4 micron wet ink thickness) onto a PET film and dried in air. The coated film is pressed against a pad containing a holographic structure and cured by UV radiation (Aktiprint® 18/2, 80 V / cm, 10 m / min) through the film. PET film is peeled off the gasket. The ratio of pigment to binder in the ink corresponds to 4: 1.

The color coordinates of the film are measured on an embossed surface in reflection and transmission using a Konica Minolta CM3610-d- colorimeter (Measurement-d8 ° geometry)

Effect obtained: Metallic hologram visible on the embossed side of a PET film.

Example 2 in UV ink

Preparation of UV ink: 6 g of UV varnish (Lumogen® OPU Primer 301 + 5% Irgacure® 2100) is added to 10 g of a dispersion of silver plates (20% pigment in methanol) in a 20 ml glass flask and gently stirred at room temperature. The resulting ink is coated with a wire preform 0 (4 micron wet ink thickness) onto a PET film and dried in air. The coated film is pressed against a pad containing a holographic structure and cured by UV radiation (Aktiprint® 18/2, 80 V / cm, 10 m / min) through the film. PET film is peeled off the gasket. The ratio of pigment to binder in the ink corresponds to 1: 3.

The color coordinates of the film are measured on an embossed surface in reflection and transmission using a Konica Minolta CM3610-d- colorimeter (Measurement-d8 ° geometry)

Effect obtained: Metallic hologram visible on the embossed side of a PET film.

Example 3 in UV ink

Preparation of UV ink: 20 g of UV varnish (Lumogen® OPU Primer 301 + 5% Irgacure® 2100) is added to 1 g of a dispersion of silver plates (20% pigment in methanol) in a 50 ml glass flask and gently stirred at room temperature. The resulting ink is coated with a wire preform 0 (4 micron wet ink thickness) onto a PET film and dried in air. The coated film is pressed against a pad containing a holographic structure and cured by UV radiation (Aktiprint® 18/2, 80 V / cm, 10 m / min) through the film. PET film is peeled off the gasket. The ratio of pigment to binder in the ink corresponds to 1: 100. Color coordinates of PET films are measured on an embossed surface in reflection and transmission using a Konica Minolta CM3610-d- colorimeter (Measurement-d8 ° geometry)

Effect: Metal hologram visible on both sides of a PET film.

Example 4 in UV ink

The UV ink in Example 2 is coated with a wire preform 0 (4 micron coating) onto a cast UV holographic image on PET, dried in air, and then compressed with respect to a pad containing a holographic image B. It is cured by UV radiation (Aktiprint® 18 / 2, 80 V / cm, 10 m / min) through the film. PET film is peeled off the gasket.

The color coordinates of the film are measured on an embossed surface in reflection and transmission using a Konica Minolta CM3610-d- colorimeter (Measurement-d8 ° geometry)

The resulting effect:

Metallic holographic image A and image B visible on each side of a PET film, blue in transmission.

Example 5 in water-borne UV ink

Preparation of UV ink: 5 g of UV varnish (Lumogen® OPU Primer 301 + 5% Irgacure® 2100) mixed with 2 g of distilled water is added to 20 g of silver plates (25% pigment in water) in a 50 ml glass flask and carefully stirred at room temperature.

The resulting ink is coated with a wire preform 0 (4 micron wet ink thickness) onto a PET film and dried in air. The coated film is pressed against a pad containing a holographic structure and cured by UV radiation (Aktiprint® 18/2, 80 V / cm, 10 m / min) through the film. PET film is peeled off the gasket. The ratio of pigment to binder in the ink corresponds to 1: 1.

The color coordinates of the film are measured on an embossed surface in reflection and transmission using a Konica Minolta CM3610-d- colorimeter (Measurement-d8 ° geometry)

Effect obtained: Metallic hologram visible on the embossed side of a PET film.

Conclusion: UV curable compositions of the present invention provide non-scaly properties that are particularly suitable for coating on holograms or embossed holograms. Extremely small particles fill the OPU lattice and cause the same reflection (Optical density 2 or higher) as the pigment deposited by the metal-vapor method.

Claims (34)

1. A method of forming a microstructure of a surface topography, especially an optically variable image (optically variable device, OPU) on a substrate, comprising the steps of: A) applying a curable composition to at least a portion of the substrate, where the specified curable composition contains A1) at least one ethylenically unsaturated resin, monomer or mixture thereof; A2) at least one photoinitiator; and a3) a metal pigment which is in the form of plate-shaped shaped transition metal particles having the largest edge lengths of 5 to 1000 nm, preferably 7 to 600 nm, and in particular 10 to 500 nm, and a thickness of 1 to 100 nm preferably from 2 to 40 and, in particular, from 3 to 30 nm; moreover, the mass ratio of the metal pigment and the binder is from 5: 1 to 1: 1000; B) contacting at least part of the curable composition with the microstructure of the surface topography, especially forming an optically variable image of the product; C) curing the composition by using at least one UV lamp. 2. A method of forming a microstructure of a surface topography, especially an optically variable image (optically variable device, OPU) on a transparent or translucent substrate, comprising the steps of: A) applying a curable composition to at least a portion of a front side of the substrate, wherein said curable composition comprises A1) at least one ethylenically unsaturated resin, monomer or mixture thereof; A2) at least one photoinitiator and a3) a metal pigment which is in the form of plate-shaped shaped transition metal particles having the largest edge lengths of 5 to 1000 nm, preferably 7 to 600 nm, and in particular 10 to 500 nm, and a thickness of 1 to 100 nm preferably from 2 to 40 nm and, in particular, from 3 to 30 nm; moreover, the mass ratio of the metal pigment and the binder is from 5: 1 to 1: 1000; B) contacting at least part of the curable composition with the microstructure of the surface topography, especially forming an optically variable image of the product; C) curing the composition by using at least one UV lamp, which is located on the back of a transparent or translucent substrate. 3. The method of claim 1 or 2, wherein the lamp is a medium pressure mercury lamp alloyed with gallium or iron. 4. The method according to claim 1 or 2, in which the photoinitiator is selected from benzophenone, compounds such as alpha-hydroxyketones, compounds such as alpha-alkoxyketones, compounds such as alpha-aminoketones, compounds of mono- and bisacylphosphine oxides, compounds of phenylglyoxylates, compounds of oxime esters and compounds onium salts (compounds of sulfonium salts and compounds of iodonium salts) and mixtures thereof. 5. The method of claim 4, wherein the photoinitiator is selected from mono- and bisacylphosphine oxides compounds and mixtures thereof. 6. The method of claim 1 or 2, wherein the curable composition comprises a mixture of a mono- and / or bisacylphosphine oxide compound with a benzophenone compound, an alpha hydroxyketone, alpha alkoxyketone or alpha aminoketone compound. 7. The method according to p. 1 or 2, in which the curable composition contains (a) from 5.0 to 0.6, especially from 5.0 to 1.0, preferably from 4.0 to 2.5 wt.% photoinitiator, (b) from 94.9 to 11.9, especially from 94.1 to 19.0, preferably from 76.0 to 47.5 wt.% of one or more ethylenically unsaturated resins, monomers or mixtures thereof, (c) from 0.1 to 87.5, especially from 1.0 to 80.0, preferably from 20.0 to 50.0 wt.%, a metallic pigment that is in the form of plate shaped transition metal particles, as defined above , moreover, the sum of the components from a) to c) is 100%. 8. The method of claim 1 or 2, wherein said metal is selected from the group consisting of Cu, Ag, Au, Zn, Cd, Ti, Cr, Mn, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt, preferably Ag and Cu, especially Ag. 9. The method of claim 1 or 2, wherein said shaped transition metal particles have a largest edge length of 5 to 1000 nm and a thickness of 1 to 100 nm and comprise hexagonal and / or triangular and / or truncated triangular prisms, moreover, prisms comprise more than 20% of the total number of molded particles of transition metals. 10. The method of claim 1 or 2, wherein said transparent or translucent substrate is selected from paper or from a thermoplastic or crosslinked polymer. 11. The method of claim 10, wherein said transparent or translucent substrate is a thermoplastic polymer selected from polyester, polyvinyl chloride (PVC), polyethylene, polycarbonate, polypropylene or polystyrene. 12. The method according to claim 1 or 2, in which the microstructure forming the surface topography means is a gasket that is selected from the group consisting of a nickel sleeve, a nickel plate, etched or laser-coated with a metal drum or other materials mounted on an opaque cylinder or a metal cylinder containing an optically variable device (OPA image) on the surface. 13. The method according to p. 12, in which the specified gasket is a Nickel plate mounted on an opaque cylinder or a metal cylinder and containing on the surface of the OPA image. 14. The method according to p. 1 or 2, in which the specified microstructure of the surface topography, especially an optically variable image (optically variable device, OPU) is applied over an existing security element, especially a hologram. 15. The protective agent obtained using the method according to one of paragraphs. 1-14. 16. The product of claim 15, which includes banknotes, credit cards, identification documents such as passports, identification cards, driver’s licenses or other identification documents, drugs, clothing, software, CDs, packaging of tobacco products or other products or packages prone to tampering with or counterfeiting. 17. The use of a product according to claim 15 for preventing falsification or reproduction on a valuable, legal, identification document, protective tag or marked product. 18. A method of forming a coating exhibiting a color change depending on the angle on a substrate, comprising the steps as defined in paragraphs. 1-14.

Images